IMO, Vlad III gets a bad rep in history ... and his story is one reason I leave the judgment of souls to God.
When you're fighting demons different rules apply and any "armty" that beheads the men, women, and children in the name of their "Profit" is without a doubt Satanic. Whatever it takes to stop them is acceptable the way I see it.
Just the "normal" results of battle with several dozen torn up corpses in your wire when the sun starts to rise is sickening. If you saw hundreds or thousands of heads and headless corpses wherever the enemy went I doubt you'd be inclined to think the Genevia Convention applied to such demonic animals.
Vlad did what he had to do and was a smart enough leader to know what would allow his inferior forces to defeat a superior force.
We could use another Vlad the Impaler today.